Automated guideway transit (AGT) is a fully automated, driverless, grade-separated transit system in which vehicles are automatically guided along a "guideway". The vehicles are often rubber tired, but other systems including steel wheels, air cushion and maglev systems have also been used in experiments. The guideway normally provides both physical support, like a road, as well as the guidance. In the case of fixed-route systems, the two are often the same in the same way that a rail line provides both support and guidance for a train. For systems with multiple routes, most AGT systems use smaller wheels riding on the guideway to steer the vehicle using conventional steering arrangements like those on a car.